Rheumatoid arthritis (RA) is a chronic inflammatory disease in which cytokines play an important role. The therapy of RA is associated with application of the drugs modulating the immune response via inhibiting the cytokine production. The common drugs used in RA therapy are methotrexate and prednisone. Recent investigations showed the importance of genetically determined differences in cytokine production in RA activity and therapy. The aim of the present study was to examine the influence of - 174 interleukin-6 (IL-6) promoter polymorphism on the efficacy of treatment of RA patients with methotrexate and prednisone. Polymerase chain reaction amplification was used for analysis of the polymorphism at IL-6 gene. Seventy patients with RA diagnosed according to the criteria of the American College of Rheumatology were investigated. The patients were divided into two subgroups. The first subgroup included patients who have obtained remission for at least 6 months after therapy with methotrexate and glucocorticosteroids. The second subgroup included patients with active disease despite at least 6 months of therapy with methotrexate and glucocorticosteroids. It has been shown that the incidence of remission after therapy with methotrexate and glucocorticosteroids was significantly lower in patients with GG genotype as compared with GC and CC genotypes p< 0.05. We suggest that -174 IL-6 promoter polymorphism may be a genetic risk factor determining the effectiveness of RA treatement with methotrexate and glucocorticosteroids.